Insulating device.



J. H. LENDI.

INSULATING DEVICE.

APPLICATION FILED JULY 7, 1905.

Patented July 30, 1912.

.jon Eleffidz;

JOHN H. LENDI, OF CHICAGO, ILLINOIS,

ASSIGNOR TO BELDEN MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

INSULATING DEVICE.

Specification of Letters Patent.

Patented July 30, 1912.

Application filed m 7, 1905. Serial no. 268,599.

To all whom it may) concern:

Be it known that I, JOHN HENRY LENDI,

a citizen of the United States of America,

and resident of Chicago, county of Cook, and State of Illinois, have invented a new and useful Improvement in Insulating Devices, of which the following is a specification.

My invention pertains to the art of insulating electrical conductors, particularly conductors on which a thin insulating coating is desired. Such conductors may be insulated by covering with a layer of thread wound upon the conductor, or by a layer of insulating material, such as rubber, varnish or other more or less flexible substance, which may be applied in liquid or plasticstate to form a covering on all sides of the conductor.

My invention pertains to the latter class of insulating devices, and has as its object the production of a uniform thin coating of varnish upon the conductor treated.

In the present practice of the art of coating electrical conductors with varnish, it is customary to draw the conductor through a quantity of the varnish contained in a tank, and after passing the conductor through such an insulating bath and a subsequent drying process, to wind the conductor thus treated upon a reel; itis customary also to pass the conductor through the hat by passing it around a cylinder partially immersed in the bath. The disadvantages and difficulties of methods of this general nature lie in the probable irregularity of the resultant insulating coatin The cylinder or roller used to guide the conductor through the insulating bath is in practice immersed less than one half of its diameter in order to keep the journals out of the bath, and as the conductor leaves the cylinder in a vertical direction it follows that the conductor leaves the cylinder or guide surface at a point of contact above the surface of the bath of insulating compound; thus an irregularity of coating is produced by the contact of the coated wire with the coated cylinder above the surface of the fluidbath. If, to avoid this subsequent contact, the wire should leave the bath in an inclined direction, the weight of the fluid compound would cause much greater irregularity by causing the compound to flow to the under side of the conductor. Another feature leading to irregularity of the insulating coating is the evaporation of the solvent of the varnish from the exposed surface of the bath, by which the bath itself is constantly changing in consistency with subsequent change in the resultant coating. Change in the coating of the wire also results from the settling to the bottom of the tank of undissolved ingredients of the resulting bath, making the solution or compound more dense in its lower strata, thus causing the lower surface of the dipped Wire to be in contact with a denser compound than the upper surface. A still further inequality of coating may result from the fact that the wire, while immersed, is in contact with the roller or guiding surface thus holding a line on one side of the wire from contact with the insulating bath in any degree, and requiring a flow of the adhering varnish from adjacent portions of the surface of the wire to'cover that line after the wire has left the bat-l1 and the guide surface; if the speed of the wire be low, and a sufficient time elapse between immersion and the entrance of'the wire into the drying oven, such redistribution of the insulating solution over the surface of the wire as may be required for an even coating of thc line of contact with the guide surface may take place, but the necessity for this redistribution of the coating after leaving the bath is a limiting function in the speed of working of such a device. 1

In my improved insulating device, evapo ration from the bathis reduced to a minimum if not entirely eliminated, the bath is kept homogeneous and constant in character, an even coating of the conductor is secured at the time of leavin the bath, and no later conditions are intro uced to cause uneven ness, thus securing an even coating and assuring conditions permitting of operating at any desired rate of speed.

In the drawing, which consists of but one figure, I have shown the arrangement of parts required in the reduction to practice of my invention, the various parts being projected diagrammatically, with section through the coating device 10 and control tank 20 to show detail of coating and con- The coating device 10 is a chamber of.

three parts, aninlet chamber 11, an outlet chamber 12, and a'conneeting web chamber 13'; the chambers 11 and 12 are formed of essentially cylindrical parts of the coating device 10, while the'web chamber 13 con-- sists of a small space between the webs 14 and 15 connecting to other the inlet and outlet chambers 11 an 12. In the web 15, is a slot 16, providing for the exit of a plurality of wires; in the web 14, are a plurality of holes such as 17, through each of which a wire, as 30, may be drawn.

In size, the holesl7 approach closely the diameter of the wire to be coated, to revent leakage of the fluid compound from t e coating chamber; this is effected by the capillary action of the fluid with the conductor and with the sides of the holes or parts, and further by the inwardly directional movement of the conductor when being treated. The slot, or exit port, on the other hand, is of restricted size only to prevent or reduce evaporation of the solvent of the coating fluid, and its edges are so remote as not to affect the surface action of the coating fluid as the conductor emerges from the bath.

The control tank, designated as a whole 20, consists of a tank 21 and cover 22, the bottom of the tank 21 having flanges into which are screwed the circuit pipe 24 and the adjustable control pipe or stand-pipe vah'e 23. The circuit pipe 25 makes connection with the control tank at or near the bottom of the tank 21, and extends thence to the pump 27; circuit pipe 26 connects with the inlet chamber 11 of the coating device, and circuit pipe 24 connects outlet chamber 12 of the coating device with the control tank 20, entrance to the control tank being made by connection with the control pipe 23 forming a part of the control tank des1g-' nated as a whole 20. Valve 28 is inserted in one of the circuit pipes 25 or 26.

The operation of the circulating and mixing system of my insulating device is as follows: The valve 28 is opened to its full eX- tent, the pump 27 is started, and insulating compound made fluid by a solvent, is poured into the'tank 21 to supply the circuit pipe 25 until varnish begins to flow from the top of control pipe 23 and the tank 21 is filled above the entrance of circuit pipe 25 but not above the top of control pipe 23. The varnish now is flowing from tank 21, through circuit pipes 25 and 26, pump 27, valve 28, and into inlet chamber 11, through web chamber 13 into outlet chamber 12 and thence through circuit pipe 24 and control pipe ".23 into the tank 21; the entire mass of varnish thus is kept in circulation, and its continued homogeneity is assured; furthermore,-the cover upon the tank 21 prevents evaporation and the openings 16 and 17 in the webs 14 and 15 are made so small as to permit only negligible evaporation, so that a continued uniformity of consistency of the by adjusting the height of the top of the control pipe 23 by screwing it down into the flange in the bottom of the tank 21, or vice versa, this means of control also regulating the height to which the surface of the varnish may rise in the slot 16 of the web 15. The speed of circulation from 21 to 11 may be controlled by the speed of the pump 27 or by the use of valve 28, that the supply to inlet chamber 11 may be consistent with the requirements of the circulation through the web chamber 13. As varnish is used fromthe coating chamber 10, the supply of the circulation system may be replenished by adding to the varnish contained in the tank 20, either continuously or intermittently. The tank 20 is designed to be closed to provide against evaporation of thegsolvent from the contained fluid, but not so closely as to promote a vacuum by reason of the lowering surface of the contained compound due to consumption of the compound. The usual looseness of a removable lid may be assumed to provide for this adjustment. f

The baking or drying oven 40 is heated by the means shown at 41 and is provided with air circulation by the fan 42; it is also provided with apertures through which wires, as 30, may pass, and it is located immediately and vertically above the coating device 10; 43 is a guide roller and 44 are take-up reels for reeling up the coated wire and also for drawing the wire through the coating device, the power being supplied by belt as shown, or by any preferred method.

The wires to be coated, as 30, are led from payout reels, over or through guides, through the small holes 17 in the lower web .14, through the web chamber 13 and out through the slot 16 in the upper web 15, thence through the drying oven 40, the finished wire 30 then passing over the guide 43 and tothe winding reels, 44. A gas jet 45 is placed adjacent to each hole 17 and so situated that the flame of the jet encircles the wire 30 to be coated immediately before the wire enters the hole 17 leading to the web chamber 13; by this jet of flame, oil and other substances foreign to the nature and structure of the wire, are burned from the wire to leave a surface thus cleaned to be coated; the metal of the wire is oxidized to some extent, resulting in a roughening of the surface of the wire to facilitate the taking up of the insulating varnish through which it is about to pass, and the wire is heated to facilitate the rapid evaporation of the solvent of the varnish immediately after the wire emerges from the bath. The direction of the wire is vertical, and as the surface of the insulating varnish in the slot 16 is horizontal, we have the wire emerging from a homogeneous liquid at right angles to the surface; therefore, all points on a given circumference of the Wire will emerge from the, liquid under exactly the same conditions as regards adherence of the varnish, and that independently of the size or speed of the wire, and the wire thus coated is ready to enter the drying oven immediately upon emerging from the insulating bath without requiring time for any redistribution of the varnish over the surface of the wire.

I do not wish to limit myself in all respects to the details shown in the accompanying drawing or covered by this specifiin any way departing from the spirit of my invention. For instance, the height of the surface of the fluid in the chamber 10 is adjustable by the stand-pipe Valve 23 and may be adjusted so that the surface of the fluid is much below the web 15.

What I claim is 1. In 'a wire-coating device, a coating chamber having ports of ingress and egress for the conductor to be coated, and means for heating the conductor prior to its entrance into said coating chamber, said means comprising a burner adapted to produce a flame surrounding the conductor, substantially as described.

2. In a wire-coating device, a coating chamber having ports of ingress and egress for the conductor to be coated, and burner adjacent to the port of ingress of said chamber and adapted to produce a flame surrounding the conductor tobe coated immediately prior to its entrance into the coating chamber, substantially as described.

3. In a wire-coating device, a coating chamber, means for passing a conductor through said coating chamber, and cleansing and oxidizing means adapted to treat a conductor before it enters said coating chamber, substantially as described.

4. In a wire-coating device, a coating chamber, means for passing a conductor through said coating chamber, and oxidizing means adapted to treat a conductor before it enters said coating chamber, substantially as described.

5. In a wire-coating device, a coating chamber, means for passing a conductor through said coating chamber, and roughening means adapted to treat a conductor before it enters said coating chamber, substantially as described.

6. In a wire coating device, a coating chamber having ports of ingress and egress for the conductor to be coated and means for heating the conductor prior to its entrance into said coating chamber, said means comprising devices for bathing the conductor in heated gases.

7. In a wire coating device, a coating chamber having ports of ingress and egress for the conductor to be coated and means for oxidizing the conductor prior to its entrance into said coating chamber, said means comprising devices for bathing the conductor in oxidizing gases.

8. In a wire coating device, a gas bath of oxidizing gases in which the conductor to be coated is treated before being coated, means for drawing the conductor through said gas bath and for coating the conductor subsewitnesses.

JOHN H. LENDI.

Witnesses DAVID S. HnLrlsl-r,

JOHN M. HUMISTON. 

